But why do people get so passionate about heirloom fruits and vegetables, and so pissed off about the bland and uniform varieties that have replaced them in our stores? This video is about as good an insight into that question as any—just look at the remarkable diversity of crops that are, or should be, part of our collective heritage.

And while free marketeers love to tout the notion of "consumer choice", there is a compelling case to be made that unchecked corporate capitalism has actually restricted our power to choose in one of the most important arenas of our lives—the food we eat and grow. By pushing the get-big-or-get-out model of farming, and combining it with the bigger-is-better model of retail, the stuff our grandparents called food has now become a niche product available to a select few.

As John of Growing Your Greens walks around this year's Heirloom Expo exhibits, we see more than 50 varieties of watermelon alone; a plethora of multicolored okra; and a literal mountain of squashes and pumpkins.